Trapped State at a Dislocation in a Weak Magnetomechanical Topological Insulator
Inbar Hotzen Grinberg, Mao Lin, Wladimir A. Benalcazar, Taylor L. Hughes, Gaurav Bahl
Abstract
So-called $w\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}k$ $t\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}p\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}l$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}s$ (WTIs, which require lattice translational symmetry for protected boundary states) are predicted to host unique topological features, but their sensitivity to disorder makes experimental confirmation challenging. The authors use a magnetomechanical metamaterial to realize a two-dimensional WTI, and experimentally demonstrate its anisotropic response. They furthermore show that the system can bind states at certain dislocation defects. This work points out an alternative path to obtaining lower-dimensional topologically protected states for robust sensors and other signal-processing devices that are resilient to disorder.